This invention relates generally to solar array assemblies, and inexpensive trusses adapted to support solar array assemblies.
A photovoltaic module or photovoltaic panel with an interconnected assembly of photovoltaic cells, also known as solar cells, is used for generating electricity. The photovoltaic module, known more commonly as the solar panel, is then used in a larger photovoltaic system to generate electricity for commercial and residential applications. A photovoltaic installation typically includes an array of photovoltaic modules or panels, an inverter, batteries and interconnection wiring.
Generally, solar arrays are sited in locations having low annual average cloud cover, for example in deserts. Deserts are also known to have high winds, low rainfall amounts, and typically are relatively warm compared to other environs. These environmental factors may lead to more rapid wear and deterioration of mechanical systems, resulting in the need for relatively more frequent maintenance and repair of such systems. As deserts are typically sparsely populated, if at all, maintenance of mechanical systems, including solar arrays, is a time consuming and expensive proposition. As such, the need for robust solar array systems requiring decreased maintenance and repair as compared to standard solar arrays has been identified.
A major limitation of these solar arrays is the cost of assembly and construction. The arrays must be massive to generate electricity at commercial levels, which makes building arrays from photovoltaic modules marginal, if not commercially impractical.
Traditionally, support structures have been assembled by attaching a single diagonal brace between two longitudinal members, requiring a means for insuring the longitudinal members are evenly spaced at a desired distance, maintained in a parallel orientation, and that the brace is positioned at the proper angle between the two longitudinal members. Once these components are properly aligned, the brace is then fastened to the longitudinal members with a spot weld or appropriate fastener at each end of the brace. A second brace is then placed between the two longitudinal members beginning at one end of the first brace and running along the opposite diagonal to the other longitudinal member, at which point the second brace is then fastened at each end to the longitudinal members. As can be seen, such a manufacturing process requires the use of two spot welds or two fasteners for each brace. This process is time-consuming and requires an operator to place a brace, fasten it, then place a next brace and fasten it, repeating the process until one side of a support structure is completed. Once one side of the support structure has been completed, the process must be repeated for each additional desired side Moreover, there are hundreds of such braces to be assembled from a solar array to produce electricity at a commercial level, a process which is labor intensive, provides significant opportunity for error, and therefore, is expensive.
What is needed to make these solar arrays commercially feasible is a method for inexpensive assembly of solar arrays from commercially available component structures.
The present disclosure describes a movable solar array which may comprise an elongated support truss having a polygonal cross-section. The support truss may have V-shaped longitudinal members forming the corners of the polygonal axial cross-section. An open web may be fixedly attached between each V-shaped longitudinal member and extend the length of the elongated truss along each side of the polygonal axial cross-section. End members may be fixedly attached at each end of the longitudinal support truss and may have a shaft extending longitudinally outwardly from the end member, where the shaft may be adapted to engage a drive provided to rotate the elongated truss. The solar array may further comprise solar panels attached along one side of the elongated truss of polygonal axial cross-section. In addition, the solar array may also comprise at least one rotatable drive capable of rotatably driving the shafts at the ends of the elongated truss to move the solar panels in relation to a change of direction of incoming solar energy.
The polygonal axial cross-section may be selected from the group consisting of a triangular cross-section and a rectangular cross-section.
The open web may be formed of steel joist webbing or bent rebar, and may be fixedly attached to the V-shaped longitudinal supports. Specifically, the open web may be welded to the V-shaped longitudinal supports. It is also envisioned that the V-shaped longitudinal supports may be L-shaped longitudinal members.
The outwardly extending shaft may be located at a position other than the center of mass of the axial cross section.
Alternatively, the disclosure describes a method for collecting solar energy comprising the steps of assembling an elongated support truss of a polygonal axial cross-section with V-shaped longitudinal supports forming corners of the elongated truss of polygonal axial cross-section, open webs fixedly attached between each V-shaped longitudinal support along each side of polygonal axial cross-section extending the length of the elongated truss, and an end member fixedly attached at each end of the support truss including a shaft extending longitudinally outwardly from the end member adapted to engage a drive to longitudinally rotate the elongated truss. Solar panels may be attached along one side of polygonal cross-section of the elongated truss. Additionally, at least one rotatable drive may be assembled which is capable of rotably driving the shafts at the end of the elongated truss to move the solar panels corresponding to a change of angle of incoming solar energy incident upon the solar panels with the movement of the sun over a day. Incoming solar energy may be captured using the solar panels by rotating each solar array in relation to a change of angle of the incoming solar energy, and the captured incoming solar energy may be transformed into electrical energy for an electrical system, which may be, for example, a battery or a municipal power grid